Wednesday, September 12, 2012

Experimental Study Finds Vouchers Don't Boost College Attendance

It all started on Twitter, and then on this blog.... now this!

BOULDER, CO (September 13, 2012) – A recent Brookings Institution report that looked at college enrollment rates of students attending voucher schools in New York City acknowledged no overall impacts of the vouchers on college attendance, but its authors trumpeted large, positive impacts for a subgroup of the voucher students: African Americans.

A new review of the report, however, questions the claim of a strong positive impact even for that group.

The Effects of School Vouchers on College Enrollment: Experimental Evidence from New York Citywas written by Matthew Chingos and Paul Peterson and published jointly by Brookings and by the Program on Education Policy and Governance at Harvard.

The report examines college enrollment rates of students participating in an experimental voucher program in New York City, which in the spring of 1997 offered 3-year scholarships worth up to $1,400 annually to low-income families.

In her review of the Brookings report, Goldrick-Rab observes that the study identifies no overall impacts of the voucher offer, but that the authors “report and emphasize large positive impacts for African American students, including increases in college attendance, full-time enrollment, and attendance at private, selective institutions of higher education.”

This strong focus on positive impacts for a single subgroup of students is not warranted. Goldrick-Rab notes four problems:

There are no statistically significant differences in the estimated impact for African Americans as compared to other students;

There is important but unmentioned measurement error in the dependent variables (college attendance outcomes) affecting the precision of those estimates and likely moving at least some of them out of the realm of statistical significance;

The authors fail to demonstrate any estimated negative effects that could help explain the average null results; and

There are previously existing differences between the African American treatment and control groups on factors known to matter for college attendance (e.g., parental education).

“Contrary to the report’s claim, the evidence presented suggests that in this New York City program, school vouchers did not improve college enrollment rates among all students or even among a selected subgroup of students,” Goldrick-Rab writes.

Consequently, this new study’s contribution to discussions of education policy is the opposite of what its authors intend. Goldrick-Rab concludes that the report “convincingly demonstrates that in New York City a private voucher program failed to increase the college enrollment rates of students from low-income families.”